Esters of hydroxydihydronorpolycyclopentadienes



Patented Feb. 26,1946 2,395,452

UNITED STATES PATENT OFFICE ESTERS OF HYDROXYDIHYDRONORPOIX- CY CLOPEN TADIENES Herman A. Bruson, Philadelphia, Pa., assignor to The Resinous Products & Chemical Company, Philadelphia, Pa., a corporation of Delaware No Drawing. Application February 20, 1943.

Serial No. 476,639

17 Claims. (Cl. 260-497) This invention relate to carboxylic esters of of the corresponding hydroxydihydro-nordicyclohydroxy-dihydronor-polycyclopentadienes and t pentadiene,

a method for the preparation of these compounds by the addition-rearrangement reaction of or- E? ganic carboxylic acids and polycyclopentadienes s of on on in a distinctly acidic environment.

It has been reported that when dicyclopenta- 0150001341 E diene is boiled with crotonic acid, depolymerizal tion of the dicyclopentadiene occurs to form cyclopentadiene which adds to the double bond of CH cm the crotonic acid, in accordance with the Diels- Alder reaction, to form a bicyclic carboxylic acid c c CH (Komppa and Beckmann, Liebigs Annalen der J} m L ll Chemie, 523, 7a (1936)), thus 1 cmcoo H CH Q C a of CHGHa i 1f +cmon-cnooon ---i n H, CH n n c E HGOOH 2o cn-cn c f l m cmooo H- n It is also known that when dihydro-dicycloc, pentadiene is oxidized with selenium dioxide in acetic anhydride solution, an ester of a dicyclo- The first Product formula 18 the more Pr le pentenyl alcohol is obtained (Alder and Stein, of the two possi l formu e, the structure of Liebigs Annalen der ch i 504, 2 0 9 3 which has been fu11y establishedinrespects other Pirsch, Berichte der Deutschen Chem. Gesellthan the relatlonshlp of ester gro p t0 the schaft, 7, 1117 1934)) methylene of the cyclopenteno ring.

' The compounds of this invention are addition- CH Ha CH CH OCOCH3 rearrangement products fl0m a carboxylic acid /1\ and a polycyclopentadiene. They are esters of C i OH on 6 7 CH 203 hydroxydihydronorpolycyclopentadiene and a H: l 8 H2 carboxylic acid. The general formula of such an H $33, H ester may be represented \C c It contains the acyl radical in the cyclopenteno ring which also contains the double bond. Upon 40 saponification this ester yields a solid alcohol melting at 30 C.

It has now been found that when organic carboxylic acids and polycyclopentadienes are mixed wherein CaH4 is a pr p nylene group whi h i in an environment which is distinctly acidic and, conjunction with the adjoining carbon atoms therefore, suificiently catalytic in nature, there forms a cyclopenteno group, R is the residue of a occurs a reaction between the two main compo- Ca bo yl c acid, and n is a small integer. nents which involves both addition of acid to the Upon saponification the above acetate yields ring system and a rearrangement of the ring syshydroxydihydronor-dicyclopentadiene, which is tem to a new type of product which, since it rean lcoh l tha is liq id at 0 C. sembles the structure of the parent polycyclo- The new esters contain one double bond in the pentadiene, is here termed the norpolycyclofive membered ring opposite the cycle holding pentadiene system. For example, acetic acid the ester group ng. It is rather surprising that combines under the influence of an acidic cataconly one double bond of the two present in the lyst with dicyclopentadiene to 'form an acetate original polycyclopentadien'e 'adds the organic carboxylic acid even when a large excess of the latter is employed. V I

As a polycyclopentadiene, there may be used any of these polymeric compounds containing two double bonds per molecule, such as dicyclopentadiene, tricyclopentadiene, tetracyclopentadiene,

mixture, since the dicyclopentadiene acts as a flux as well as a reactant. The various polymers may be obtained as cry talline solids by heating cyclopentadiene at 150 C. to 200 C. in a closed vessel. They possess the following general formula:

rCH

where n is a number varying from zero to a small integer such as 1, 2, or 3.

As an organic carboxylic acid there may he used an aliphatic, arylaliphatic, cycloaliphatic, heterocyclic, or aromatic carboxylic acid. The acid may be monocarboxylic or polycarboxylie in which latter case mono-esters or poly-esters thereof may be formed with one or more of the carboxylic groups of the acid. The acid may be straight-chained, branched-chained, acylic, cyclic. saturated, or unsaturated. The acid may be rela tively strong or weak, although in the latter case proper choice of catalyst is generally necessary to hasten the reaction and to provide a. practical yield in a reasonable time. as will be further explained below. Acids which may be reacted with the polycyclopentadienes having two double bonds per molecule in a distinctly acidic environment are typified by the following acids: Formic, acetic,

catalyst depends upon the particular acid used."v

Such catalysts as sulfuric acid, alkyl sulfonic acids such as butyl sulionic acid or aryl suli'onic acids such as benzene or naphthalene sulionic acid are effective with carboxylic acids having ionization constants as low as 1.3x 10-. For acids below this value, the reaction must be catalyzed with in promoting the desired reaction which includes propionic, butyric, isobutyric, valerlc, isovaleric,

caproic, caprylic, capric, lauric, myristic, palmitic, stearic, lactic, glycollic, e-hydroxy-isobutyric, acrylic, methacrylic, phenylacrylic, crotonic, o nnamic, chloroacetic, bromoacetic, dichloroacetic, trichloroacetic, thiocyanoacetic, aor fl-chlorepropionic, chlorccrotonic, methoxyacetic, ethoxyacetic, butoxyacetic, butoxyoropionic, phenoxyacetic, undecylenic, oleic, lino1eic,levulinic, oxalic, succinic, pimelic, adipic, sebacic. benzoic, salicylic, phthalic, naphthenic, furoic, abietic, haphthoic, tricarballylic, citric, tartaric, ohloromaleic, chlorosuccinic,y-acety1 y-methyl pimelic.

When the orga'nic'carboxylic acid has a dissociation constant of about 1.5x 10- -01 more, the acid itself imparts sufllcient acidity to the reaction mixture to promote the reaction between polycyclopentadiene and acid. The reaction may be said to be self-catalyzed. At the same time the reaction oithes'e relatively stronger carboxylic acids is further accelerated by the presence of a mineral acid. such as sulfuric or hydrochloric acid, I

addition and rearrangement;

The boron fluoride group of catalysts is one of great importance. .Boron trifluoride by itself or from its coordination complexes activates weak acids to such an extent that they readily combine with the polycyclopentadienes. This is in agreement with the known behavior of boron trifluoride and other acidic catalysts in forming ansolvo acids or complexes with weak acids which then act like strong acids. By this means weak organic acids such as octoic, lauric, oleic, stearic, abietic, tetrahydroabietic, hexahydrobenzoic, and other higher aliphatic, arylaliphatic, or cycloaiiphatic carboxylic acid are readily reacted with a polycyclopentadiene. At the same time boron trifluoride as a catalyst is not without benefit in the case of reactions involving relatively stronger carboxylic acids.

The addition of an organic carboxylic acid to di-; tri-, tetra-, or penta-cyclopcntadiene takes placepreferably at temperatures from about C. to C. although reaction often starts even below room temperature. Since dicyclopentadiene begins to crack into cyclopentadiene-above C., it is desirable that this temperature be not exceeded in the case of this reactant in order to obtain the best yields. In the case of tricyclopentadiene and the higher polycyclopentadienes, the depolymerization temperatures lie above C. and, in the case of these compounds, temperatures up to about 200 C. can be employed, if necessary. In cases where it is advantageous to employ an inert solvent in order to obtain a homogeneous reaction mixture, ethylene dichloride or tetrachlorethane is suitable. v The high melting I polycyclopentadienes, notably the tetraand the penta-cyclopentadien'e, are advantageously dissolved in dicyclopentadiene so as to form a lowmelting or liquid eutectic and are thus rendered amenable to esteriflcation.

Tricyclopentadiene addsthe organic carboxylic acids according to the present invention as follows (using acetic acid as an example).

on on on, o on HfiOa omcoon+ n, H: 1!

11 n n---- H on on on. ol o oh on I H: l HI l 4 cmcoo-cn-l- H n Upon saponiflcation the above acetate yields a crystalline alcohol melting at 115 C.

softening agents for synthetic resins, synthetic or natural rubber, as hydraulic fluids, as components for printing inks, nitrocellulose compositions, and as intermediates for insecticides, textile finishing agents, waxes, resins, wetting agents, and other industrialapplicatlons. The residual double bond present in their molecule is still 011-- pable of adding hydrogen, halogen, and thiocyanogen to yield well-defined addition products.

The following examples illustrate this invention. Parts are by weight.

Example 1 A mixture of 132 parts of dicyclopentadiene, 106 parts of 87% formic acid and 10 parts of 40% sulfuric acid was stirred rapidly for 5 hours at 60-70" C; The product was washed with wai ter, taken up in toluene, and the toluene layer washed successively with dilute soda solution and water. After the toluene was evaporated, the residual oil was distilled under reduced pressure to yield 126 parts of dihydronordicyclopentadienyl formats as a colorless oil, boiling at 111- 7 112 (1/10 mm, having a. pleasant odor, and pos- 'sessing the probable formula A mixture consisting of 250 parts of glacial acetic acid, 4 parts of 98% sulfuric acid, 6 parts of water, and 100 parts of dicyclopentadiene was stirred and heated at 60-70 C. for 4 hours under a reflux condenser. The dark solution obtained was cooled and poured into 1000 parts of water. An oil layer separated and some ethylene dichloride was added to assist in stratification. The lower oil layer was drawn off, washed several times with water, with dilute soda solution, and finally again with water. The solvent solution was dried, the solvent stripped 011, and the -7 oil distilled under reduced pressure.

The acetic ester of hydroxydihydronordicyclopentadiene distilled between 95 and 100 C. at 1 mm. absolute pressure of mercury as a colorless liquid having a pleasant melon-like odor. Upon redlstillation at 10 mm. it boiled at 119-12*1 C.

The yield was 125 parts. The following constants were determined for the product:

Upon saponification with alcoholic potassium hydroxide solution, dihydronordicyclopentadienyl I acetate yielded hydroxydihydronordicyclopentalit diene, having the following properties: boiling point 116/10 mm., N 1.5249 and d4 1.0773. This alcohol is a colorless oil of faint camphoraceous odor.

Example 3 t A mixture consisting of 132 parts of dicyclopentadiene, 400 parts of. propionlc acid, 5.3 parts of 98% sulfuric acid, and 8 parts of water was heated at 60-70" C. for five hours. The product was cooled, then poured into 1000 parts of water. Toluene was added thereto and an oil layer separated.

The toluene extract was washed \several times with cold water, then with dilute (1%) soda solution, and finally with water. Uponevaporation of the toluene, 169 parts of residual oil was obtained. This was distilled under reduced pressure. The dihydronordicyclopentadienyl propionate thus obtained came over at 100-110 C./

1-2 mm. as a colorless oil having a melon-like odor in a yield of 137 parts. Upon redistillation at 10 mm. it boiled at 131-133 C. and, possessed the following constants:

ND 1.4901 a." 1.0501

1 Upon saponification by boiling with an excess of aqueous 10% sodium hydroxide solution for five hours hydroxydihydronordicyclopentadiene identical with that described in Example 2 was obtained.

Example 4 A mixture of 132 parts of dicyclopentadiene and 132 parts of chloroacetic acid was stirred and heated for 12 hours at 95 C. The product was then distilled under reduced pressure. After the unchanged dicyclopentadiene and chloroacetic acid had distilled off, the desired ester, the chloroacetate of hydroxydihydronordicyclopentadiene, came over at -130 C./l mm. as a colorless oil. Upon redistillation it boiled at 154-156 C.,/10 mm. and possessed the following constants:

ND 1.5111 de 1.1916

The yield was 90 parts. While the above ester was prepared without addition of a separate acid as a catalyst, by the use of live parts of 40% sulfuric acid or two parts of benzene sulfonic acid as a catalyst the time of condensation may be cut to five hours and the yield materially increased.

Equivalent weights of bromoacetic acid, dichloro or dibromo-acetic acid, or trichloroacetic acid may be used in the place of the chloroacetic acid and good yields of the corresponding esters obtained without addition of another acid. Thus, acids as strong as chloroacetic acid or stronger can act as their own catalyst, since they supply a distinctly acidic environment.

Example 5 A mixture of 66 parts of dicyclopentadiene, 174 parts of levulinic acid, and 5 parts of 40% sulfuric acid was stirred for 8 hours at 60-65 C. The mixture was then cooled and mixed with an equal volume of ethylene dichloride. The solvent layer was separated and washed thoroughly with water, wtih soda solution, and finally again with water. The ethylene dichloride was removed by evaporation under re-' duced pressure and the residual oil weighing 101 parts was distilled in vacuo at 1 mm. Dihydronordicyclopentadienyl levulinate came over as a pale yellow oil at 158-160" C./1 mm. in a yield. of 83 parts. Upon redistillation at 10 mm. it boiled at 190 C. and possessed the following constants:

Example 6 A mixture of 141 parts of tricyclopentadlene, 300 parts of glacial acetic acid, 4 parts of 98% sulfuric acid and 6 parts of water was rapidly stirred and heated at 65-70 C. for six hours. The mixture was cooled, washed with water, taken up in toluene and the toluene solution washed successively with dilute soda solution and water. The toluene was distilled off under reduced pressure to yield 168 parts of crude dihydronortricyclopentadienyl acetate, which upon fractionation in vacuo at 1 mm. distilled at 150-155 C. as a pale yellow oil. Upon redistillation at 11 mm. it came over at 190-194" C. as a colorless, somewhat 'viscid liquid. ,Upon saponification it yielded-the corresponding dihydronortricyclopentadienyl alcohol as a. colorless viscous oil of aboiling point 180-185 C./11, mm., which gradually solidifies to a waxy mass, melting at 115-1'16 C. after recrystallization from nitromethane.

7 Example 7 500 parts of dicyclopentadiene was heated for 12 hours at 190-200 C. and the wax-like mixture of tri-, tetra-, pentaand higher polycyclopentadienes'obtained was stirred for 12 hours at 90- 100 C. with'2500 parts of glacial acetic acid containing 100 parts of 40% sulfuric acid. The

product was filtered hot and the filtrate evapv CH CH\ CH: CH: l CH '0 on CH: CH: CH;CCH-l H n n=1, 2, and 3.

Example 8 A mixture of 132 parts of dicyclopentadiene, 358 parts of caproic acid, 10 parts of 98% sulfuric acid was stirred and heated at 90-l15 C. for eight hours. The mixture was allowed to stand overnight, washed with water, with dilute sodium hydroxide solution several times, and again with water, dried, and distilled under reduced pres- C. for five hours with constant stirring.

product was cooled, washed with water, with soda solution, and finally with water, then dried and sure. The dihydronordicyclopentadienyl caproate distilled as a pale yellow liquid between 169 C. and 173 C. at 10 mm. and boiled at 120-13'O C./2 mm. The product had a saponification number of 217, compared with a theoretical number of 226.

Example 9 A mixture consisting of 132 parts of dicyclopentadiene, 172 parts of crotonic acid, 10 parts of naphthalene sulfonic acid and 10 parts of sulfuric acid was heated under refiuxat 95-105 The distilled under reduced pressure.

The dihydronordicyclopentadienyl crotonate having the formula CH CH:

distills over as a pale yellow oil at -128-130 C./3 mm.

Example 10 A mixture of 132 parts of dicyclopentadiene, 104 parts of alpha-hydroxyisobutyric acid and 10 parts of aqueous 40% sulfuric acid was stirred and heated at 95-98 C. for six hours. The prodnot was cooled, washed with water, taken up in an equal volume of toluene, washed with dilute soda solution, and finally with water, and dried. The toluene was evaporated off and the residual oil (192 parts) was distilled under reduced pres-- sure. The fraction boiling at 135-442 C./2 mm.

' was a colorless liquid, dihydronordicyclopentadienyl alpha-hydroxyisobutyrate. 104 parts. at 155-157 C./10 mm.

Example 11 To 212 parts of %lactic acid, 20 parts of 98% The yield was sulfuric acid was added gradually with cooling.

Dicyclopentadiene (132 parts) was then added. The mixture was stirred and gradually heated under a reflux condenser on a steam bath.- An exothermal reaction occurred which raised the temperature to about 113 C. When this reaction had subsided, the mixture was stirred continuously and heated for 3 hours at C. It was then cooled, washed with water, and an oil layer separated. The oil was taken up in toluene and the toluene solution shaken with powdered calcium hydroxide to destroy residual acidity. The filtered solution was then distilled under reduced pressure.

The lactate of hydroxydihydronordicyclopenta- .diene distills as a colorless liquid boiling at 150-155 C./8 mm.

Example 12 A mixture of 66 parts of dicyclopentadiene, 22.5.

parts of anhydrous oxalic acid, and 75 parts of tetrachloroethane was stirred and heated under reflux at 135-140 C. for five hours. The product was cooled, then washed with water and dilute soda solution until free from acidity, and finally washedagain with water. The dried liquid was evaporated under reduced pressure to remove the tetrachloroethane. The residual dark, viscous product consisted essentially of the crude diester,

7 the oxalate of hydroxydihydronordicyclopenta- Upon redistillation thisester boiled following constants:

dlene, in a. yield of 75 parts. It boiled above 230 C./1 mm. When this oil was boiled with a solutlon of 85 parts of sodium hydroxide in 250 parts of alcohol and 100 parts of water for 8 hours, hydroxydihydronordicyclopentadiene was obtained in 90% yield.

Example 13 formula CH CH! Cgl C \CH OH H: I

000- H-l- H C 2 distilled over at 174-176 C./3 mm. as a colorless oil. The yield was 138 parts. On standing the product solidified, and upon recrystallization from methanol formed colorless crystals, melting at 93-94 C.

Example 14 To a stirred mixture of 144 parts of alphaethyl hexoic acid and 132 parts of dicyclopentadiene 30 parts of boron trifluoride-diethyl ether complex (BF3.C2H5--OC2H5) was added. An exothermal reaction set in during which the temperature of the mixture reached 60 C. After the rapid evolution of heat had subsided, the mixture was gradually heated to 90 C. during the course of one and one-half hours, and then held at 90 C. for two hours longer while it was stirred constantly. The. resulting product was cooled, Washed twice with water, then with sodium carbonate solution, and finally again with water. It was then dried and distilled in vacuo. The final product thus obtained corresponded in composition to the ethyl hexoate of hydroxydihydronordicyclopentadiene. It distilled at 150-152' J2 mm. as a colorlessoil in a yield of 110 parts.

Example 15 (a) To a stirred mixture of 200 parts of lauric acid and 132 parts of dicyclopentadiene 30 parts of boron trifiuoride-diethyl ether complex was added. The mixture was then heated at 80- 85 C. for five hours, and worked up as in Example 1. The product obtained was the lauric acid ester of hydroxydihydronordicyclopentadiene which distilled at 195-200 C./2 mm. as a colorless oil in a yield of 145 parts. It possessed the N 1.4797; d4 0.955; Sap. No. 167 (theory 169) (b) The reaction of lauric acid and dicyclopentadiene was repeated with the use of 15 parts of boron trifluoride gas in the place of the ether complex. The same product was obtained in about the same yield.

Example 16 A mixture of 142 parts of stearic acid, 66 parts oi dicyclopentadiene and 10 parts of boron trifiuorlde-diethyl ether complex was stirred at 70 C. ror seven hours, then cooled, washed and worked up as in Example 1. The resulting product, the stearic acid ester of hydroxydlhydronordicyclopentadiene, distilledat 230-240 02/3 mm. as a pale yellow oil. The yield was parts. Upon redistillation it boiled at 240-243 C./2 mm. and possessed the following constants:

N9 1.4.792; d4 0.937; Sap. No. 140 (theory 135) Example 17 A mixture of 141 parts of oleic acid, 66 parts of dicyclopentadiene and 10 parts of boron trifiuoride-diethyl ether complex was stirred at 55 C. for six hours. The mixture was washed, neutralized and worked as in Example 1. Theresulting product, the oleic acid ester of hydroxydihydronordicyclopentadiene, distilled at 240- 250 C./2 mm. as a pale yellow oil in a yield of parts.

Example 18 A mixture of 110 parts of undecylenic :acid, 79 parts of dicyclopentadiene and 10 parts of boron trifluoride-dietnyl ether complex was stirred at 55-60 C. for five hours. The cooled mixture was washed, neutralized, and worked up as in Example 1. The resulting product, the und'e cylenic acid ester of hydroxydihydronordicyciopentadiene, boiled at l85-19u C./2 mm. The yield was 85 parts.

Example 19 To a stirred mixture of 141 parts of linseed oil fatty acids and 66 parts of dicyclopentadiene 10 parts of boron trifiuoride-diethyl ether complex was gradually added at 55 C. The mixture was stirred for six hours thereafter at 55 C., then cooled, taken up in toluene and washed with water, then with dilute soda solution and finally with water. The toluene was distilled off and the residual oil distilled in vacuo. The fraction boiling at 245-250 C./2 mm. was a light yellow oil corresponding to the esters of hydroxydihydronordicyclopentadiene and the mixed fatty acids present in linseed oil. The yield was 90 parts of pure esters,

Example 20 Example 21 To a stirred mixture of 61 parts of benzoic acid, parts of ethylene dichloride, and 66 parts of dicyclopentadiene 5 parts of boron trifluoridediethyl ether complex was added. An exothermic reaction took place, the temperature rising to 45 C. The mixture was stirred at 45 C. for five hours, then cooled, washed with cold water, followed by a wash with sodium carbonate solution and a final water wash. The ethylene dichloride was evaporated oil in vacuo, and the residual oil parts) distilled in vacuo. The product, the benzoic acid ester of hydroxydihydro nordi- The product was 6 cyclopentadi'ene distilled at 170-175, C./2 mm. as

a colorless oil in a yield or 78 parts. Upon redistillation it boiled at 164 C./2 mm.

'Eilidmple 22 Amixture or 54 parts or dicyclopentadiene, 84 parts or naphthenic acids (average molecular weight 204), and 2 parts of boron trifluoride-diethyl ether complex was stirred at 45-50 C. for two hours. The mixture was then cooled, washed with water and soda solution, dried and distilled in vacuo. The resulting product, the naphthenic acid ester of hydroxydihydronordicyclopentadiene. distilled as a pale yellow oil at 175-195 C./2

' Example 23 A mixture or 148parts of phthalic anhydride (1 mol) and 32 parts of methanol was heated under reflux for three hours, to form the monophthalic acid methyl ester. To this was added 132 parts of dicyclopentadiene and 5 parts of boron trifluoride-diethyl ether. The mixture was stirred at 90 C. for five hours, then cooled,

washed with water and soda solution, dried and distilled in vacuo.

The mixed ester,

oooom (CioI-Ii:=the dihydronordicyclopentadienyl residue), distilled at 205-2l5 C./2 mm,- as a viscous,

almost colorless oil in a yield of 180 parts. Upon redistillation it boiled at 208-212 C./2 mm.

It is useful as a plasticizer for synthetic rubber, synthetic resins, and nitrocellulose.

In a similar manner phthalic acid monoethyl ester yields the corresponding dihydronordicyclopentadlenyl ethyl phthalate. It was obtained as 0 a colorless oil boiling at 190-200 C./1 mm.

By using phthalic acid mono-n-butyl ester, the

corresponding dihydronordicyclopentadienyl butyl phthalate was obtained as a pale yellow oil boiling at 230-235 C./3 mm.

Example 24 A mixture or 59.4 parts of crystalline tricyclopentadiene having two double bonds per molecule, parts of isobutyric acid, and 5 parts of boron trifluoride-diethyl ether in 50 parts of ethylene dichloride was stirred at -90-95 C. for six hours. The mixture was then cooled, washed with water and soda solution, dried, and distilled in vacuo. The resulting product, the isobutyric acid ester of hydroxydihydronortricyclopentadiene, distilled at 175-185 C./3 mm. as an almost colorless oil. Upon redistillation the pure compound boiled at 168-170 C./2 mm.

Example 25 The acetate or hydroxydihydronortricyclopentadiene distilled at l50-155 C./1 mm. as a pale yellow oil.

The acetate oi hydroxydihydronortetracyclopentadiene distilled at l-205 C./l mm. as a.

pale yellow oil.

The residual oil consisted essentially of the acetate of hydroxydihydronorpentacyclopentadiene and higher hydroxydihydronorpolycyclopentadienes.

Example 26 A mixture of 73 parts of adipic acid, 132 parts of dicyclopentadiene, 200 parts of ethylene dichloride and 7 parts' of boron trifluoride diethyl ether complex was stirred at 60 C. for six hours. The reaction mixture was cooled, filtered to remove traces of adipic acid, washed several times with "water and soda solution, and dried. The dried ethylene dichloride solution was evaporated to dryness in vacuo at C. The residual product was a dark viscous mass weighing parts consisting essentially oi di-dihydronordicyclopentadienyl adipate. It could not be distilled in high vacuo without decomposition. I

In the above examples, the reaction of pure or relatively pure polycyclopentadienes with carboxylic acids has been described. In place of such polycyclopentadienes there may be used crude products or mixtures of hydrocarbons containing 5% or more of polycyclopentadienes having two double bonds per molecule. Such mix-- tures are obtained in the thermal cracking of 1 petroleum as, for example, in the manufacture oi gasoline or in the manufacture of water gas. This new reaction of polycyclopentadienes provides a new method for separating certain components of'mixtures of hydrocarbons and gives new utility to them.

This application is a continuation-in-part of my application Serial No. 443,724, filed May 20,

I claim:

1. A method for preparing carboxylic esters of hydroxydihydronorpolycyclopentadiene h a vi n g the acyl group attached through oxygen to one terminal cycle and having a double bond in the opposite terminal cycle, which comprises reacting by addition and rearrangement an organic carboxvlic acid and a. crystalline polycyclopentadiene having two double bonds and one to tour endomethylene cycles per molecule at a temperature below the depolymerization temperature of said polycyclopentadiene in the presence of an acidic catalyst which does not act as an oxidizing agent during the reaction.

2. A method for preparing carboxylic esters of hydroxydihydronorpolycyclopentadiene h a v i n g the acyl group attached through oxygen to one terminal cycle and having a double bond in the opposite terminal cycle, which comprises reacting by addition and rearrangement an organic monocarboxylic acid and a crystalline polycyclopentadiene having two double bonds and one to four endomethylene cycles per molecule at a temperature below the depolymerization temperature of said polycyclopentadiene in the presence or an acidic catalyst which does not act as an oxidizing agent during the reaction.

3. A method for preparing carboxylic esters of hydroxydihydronorpolycyclopentadiene having the acyl group attached through oxygen to one terminal cycle and having a double bond in the opposite terminal cycle, which comprises reactingbyadditionandrearrangementinthepresence of boron trifluoride an organic carboxylic acid and a crystalline polycyclopentadiene having two double bonds and one to four endomethylene cycles per molecule at a temperature below that at which depolymerization of said polycyclopentadiene occurs.

4. A method for preparing carboxylic esters of hydroxydihydronorpolycyclopentadiene having the acyl group attached through oxygen to one terminal cycle and having a double bond in the opposite terminal cycle, which comprises reacting by addition and rearrangement in the presence of boron trifluoride an organic monocarboxylic acid and a crystalline polycyclopentadiene having two double bonds and one to four endomethylene cycles per molecule at a temperature below that at which depolymerization of said polycyclopentadiene occurs.

5. A method for preparing carboxylic esters of hydroxydihydronorpolycyclopentadiene having the acyl group attached through oxygen to one terminal cycle and having a double bond in the opposite terminal cycle, which comprises reacting by addition and rearrangement in the presence of sulfuric acid an organic carboxylic acid having a dissociation constant of at least 1.3X land a crystalline polycyclopentadiene having two double bonds and one to four endomethylene cycles per molecule at a temperature below that at which depolymerization of said polycyclopentadiene occurs.

6. A method for preparing carboxylic esters of hydroxydihydronorpolycyclopentadiene having the acyl group attached through oxygen to one terminal cycle and having a double bond in the opposite terminal cycle, which comprises reacting by addition and rearrangement a monocarboxylic acid having a dissociation constant of at least l.5 and a crystalline polycyclopentadiene having two double bonds and one to four endomethylene cycles per molecule at a temperature below that at which depolymerization of said polycyclopentadiene occurs.

7. The process of claim 6 in which the polycyclopentadiene is dicyclopentadiene.

8. A method for preparing carboxylic esters of hydroxydihydronordicyclopentadiene having the acyl group attached through oxygen to one terminal cycle and having a double bond in the opposite terminal cycle, which comprises reacting by addition and rearrangement an organic carboxylic acid and dicyclopentadiene having two double bonds per molecule at a temperature below about 150 C. and in the presence of an acidic catalyst which does not act as an oxidizing agent during the reaction.

9. A method for preparing carboxylic esters of hydroxydihydronordicyclopentadiene having the acyl group attached through oxygen to one terminal cycle and having a double bond in the opposite terminal cycle, which comprises reacting by addition and rearrangement in the presence of a boron trifiuoride catalyst a monocarboxylic acid and dicyclopentadiene having two double-bonds per molecule at a temperature below about 150 C.

10. A method for preparing carboxylic esters of hydroxydihydronordicyclopentadiene having the acyl group attached through oxygen to cha terminal cycle and having a double bond in the opposite terminal cycle, which comprises reacting by addition and rearrangement in the presence of sulfuric acid a monocarboxylic acid having a dissociation constant of at least 1.3 10- and a dicyclopentadiene having two double bonds per molecule at a temperature below about C.

11. An acid-catalyzed, addition-rearrangement product of a carboxylic acid and a polycyclopentadiene having one to four endomethylene cycles and a double bond in each of the two terminal cycles, said product being a hydroxydihydronorpolycyclopentadiene ester of the carboxylic acid and having a double bond in a terminal five-membered cycle.

12. An acid-catalyzed, addition-rearrangement product of a monocarboxylic acid and a polycyclopentadiene having one to four endomethylene cycles and a double bond in each of the two terminal cycles, said product being a hydroxydihydronorpolycyclopentadiene ester of the monocarboxylic acid and having a double bond in a terminal five-membered cycle.

13. An acid-catalyzed, addition-rearrangement product of an aliphatic carboxylic acid and dicyclopentadiene having one endomethylene cycle and a double bond in each of its cycles, said product being a hydroxydihydronordicyclopentadiene ester of the aliphatic carboxylic acid and having a double bond in a terminal five-membered cycle.

14. An acid-catalyzed, addition-rearrangement product of acetic acid and dicyclopentadiene having one endomethylene cycle and a double bond in each of its cycles, said product being a hydroxydihydronordicyclopentadiene ester of acetic acid and having a double bond in a terminal fivemembered cycle.

15. An acid-catalyzed, addition-rearrangement product of lauric acid and dicyclopentadiene having one endomethylene cycle and a double bond in each of its cycles, said product being a hydroxydihydronordicyclopentadiene ester of lauric acid and having a double bond in a terminal fivemembered cycle.

16. An acid-catalyzed, addition-rearrangement product of ehloroacetic acid and dicyclopentadiene having one endomethylene cycle and a double bond in each of its cycles, said product being a hydroxydihydronordicyclopentadiene ester of chloroacetic acid and having a double bond in a terminal five-membered cycle.

17. An acid-catalyzed, addition-rearrangement product of chloroacetic acid and a polycyclopentadiene containing one to four endomethylene cycles and having a double bond in each of the two terminal cycles, said product being a hydroxydihydronorpolycyclopentadiene ester of chloroacetic acid and having a double bond in a terminal five-membered cycle.

HERMAN A. BRUSON. 

